How the fuck do you handle PBR values?Anonymous04/23/17(Sun)10:46:04No.561739

So there's these charts floating around that claim to have the correct values for physically realistic results when using PBR workflow for something like Unreal Engine 4. But all the artist work or included samples that come with the engine don't adhere to any fucking standards at all. Their textures appear to have completely random values for luminosity etc. that don't follow these charts at all.

For example this chart claims the mean luminosity of the albedo map for painted metal is around 94, but it's fucking impossible to make any red or yellow painted metal while keeping the medium at 94 because it looks ultra dark and de-saturated. Am I a retard and doing this shit incorrectly? It's confusing as hell. I have no idea how bright to make any of my textures, I thought PBR was supposed to remove guess work but all I've been doing is guessing how bright or dark to make my fucking albedo maps.

Do the values you've entered look like the material you're trying to emulate? If yes, job done. If no, tweak until satisfied. make your albedo around 50% luminosity and multiply it with a float in your shader for easy tweaking.

>>561739>any game engine>physically basedI want this meme to die, along with the metalness map part, it just makes everything look the same, not to mention those nasty artifacts on metal/non-metal border. Also these reflectivity values are bullshit, most non-metal dont have colored reflection

>>561809I don't work with shaders a whole lot, but It was my understanding that a metalness map influences the reflective scatter, does it not? i.e how rough vs smooth the surface looks. Why wouldn't you use that?

I came here to moan about this as a separate thing but this thread seems as somewhat relevant to the incoming whine-fest from me....

What's the fucking point? See attached image - this is part of a floor texture I've been working on. What you see here is literally just the diffuse map I painted in 'shop, plugged into a VRay material that I just ran out as a test before creating all the other maps in SP...

>>561826If you want to compare you render in Vray with your render in Substance it would help tremendously if you use the same HDRI image as illumination/reflection sphere.

Reflect map, reflect gloss IOR map and a roughness map? You only need the roughness map. For such a flat surface you use height AND normal? Doesn't seem overkill to you?

So far your scene doesn't provide anything which would make these effects stand out. IS there something to reflect? If you don't have a light at grazing angles you won't see fresnel effect. There is no direct light reflection so you don't see the roughness variation.

That beeing said, the reflections in an realtime engine will always look different than the reflections in an traditional render. At first sight those in engine might look sharper and stronger, but the reflections in Vray will look more realistic if done right.

i'm not using an HDRI in the Max scene - just a JPG in a dome to add a little colour to the GI. Majority of illumination comes from IES lights nearby.

I have an approximately similar HDRI in SP though but trouble is - SP dumps your model in the middle of the sphere - this model, for obvious reasons, needs to be way down low - I can't figure out a way round that. Suggestions?

All those maps is crazy - sure, but those are the maps it spits out, so after a good bit of tinkering with different combinations - that was the best result I could get.Trust me - roughness alone did not work. It looked shit. In fact - taking out any map *but* the roughness map made it look terrible. The roughness actually seems to be doing very little.

Yeah - I'll concede the heightmap + normal is overkill, but still - it is giving a more detailed result than either one of those maps by itself (not by much, I admit...)

There are a number of ies lights around the scene which I was hoping the puddles would pick up at least a tiny amount. There's also a lot of wetness over the sidewalk in general - again I was hoping this would pick up at least *some* direct reflections of the neon tubes around the scene....

Hey I'm not the guy you're talking to, but I can hopefully lend a little bit of knowledge on this...

'Metalness' is distinct from reflectiveness / roughness. Real world electricity conducting materials (ie. metals) have very very low amounts of diffusion - practically 0% in most cases (gold for example).So this means that nearly 100% of the light that we see when we look at metals is direct reflection. This raises the question - how does metal appear to have any colour to it? Why does gold appear 'gold' and not just a mirror of the colours in space around it?

This is because metals, unlike almost all other substances in the known world, actually colourize the direct reflections they send back.

So metalness is not simply influencing the amount of reflected light, but also it's colour, which - in PBR engines - is derived from the diffuse input.

('diffuse' in this instance is something of a misnomer, as there is *no* diffusion - this is why, I guess, it is referred to as 'albedo' in PBR engines).

A lot of what I've said here is based on things i have literally only just read about, and have only half digested - so I may have some stuff wrong. So don't bother flaming me if I have.

There are two really essential articles on the Marmoset site that anyone interested in PBR shading should read:

>>561812metalness maps are only used to tell the engine which part of a surface is metallic and which isn't. the value is either 0 (non-metallic a.k.a dielectric) or 1 (metal). in some cases you can use values in between 0 and 1 for example when you have a piece of dirt covering a metal surface. if you made a sphere of gold, the metalness map would be pure white. if you made a sphere of gold sitting on a plastic cup, you would make the UV's for the sphere 100% white (metal) and for the cup 100% black (non-metal, it's plastic)it's important to remember that only the upper most surface is whats counted. if you made an object that has painted metal, your metallic value will actually be ZERO because the paint is the upper most layer of the material, NOT the metal. it's the same with something like a beverage can. it's technically made out of aluminium, however the outer most layer is covered in a non-metallic surface which means it is NOT metallic. only bare exposed metallic surfaces should be configured as a metallic surface.

roughness / smoothness are completely different and handled on a different texture map (roughness map if you're in UE4, some programs call it a gloss map or smoothness)

here's an example of a sphere where on the left it is 100% non-metal and on the right it's 100% metal. other than that they use the exact same texture information:https://cdn2.unrealengine.com/blog/metalness01-600x300-694626521.png

here's an example of a non-metal sphere with very low roughness on the left, average roughness in the middle and very high roughness on the right:https://cdn2.unrealengine.com/blog/physicshadingheader-770x250-996585692.png

People are randomly using metalness values as an addition to roughness values, on all sorts of objects which are not supposed to be metallic - presumably thinking that metalness is the opposite of roughness.

It isn't. It's a parameter very specifically intended for electricity-conducting materials. If you are making a shiny plastic object, it's metalness value should be set to 0, regardless of how shiny it is - it isn't metal.